This proposal describes research concerned with memory development in children 1 to 5 years of age. The main goals of the research are: (1) To delineate the basis of improved recognition performance over the preschool years; (2) To determine the source of preschool children's general incompetence in recall tasks, as well as the basis of the age-related improvement that is observed in recall; and (3) To develop a methodology which is both appropriate for adequately examining the full gamut of memory skills available to preverbal children, and sensitive to an ecological view of cognition. Laboratory experimental tasks will be used to evaluate how very young children's proficiencies and deficiencies at acquisition, knowledge, retention, recognitory, response, encoding, search, generative, and verbal skills affect their memories. Field observations will be used to investigate when, and how, very young children utilize memory in their natural habitats, and studies will be carried out to determine how they use memory in problem-solving situations.